1,721,068 research outputs found
A-t-on besoin d'une agence fiscale européenne? Gènese et contours d'une idée en devenir
No full textThe intensification of administrative cooperation in tax matters raises the prospect of greater institutionalisa-
tion. In an open letter to the European Commissioner for Taxation, around one hundred European tax law
professors support the creation of a European Tax Agency. The response is encouraging.L’intensification de la coopération administrative en matière fiscale amène à envisager une plus grande
institutionnalisation. Dans une lettre ouverte au commissaire européen à la fiscalité, une centaine de
professeurs européens de droit fiscal appuient la création d’une agence fiscale européenne. La réponse est
encourageante
Microstructural Properties of Microporous a-Hematite ceramics Investigated by fractional factorial design
No full textCrystallisation of Al2O3-TiO2 sol-gel systems
No full textAl2O3-TiO2 thin films and powders were synthesised from acid catalyzed sols of aluminium and titanium alkoxides containing acetyl acetone as a chelating agent. The crystallization of the system was studied as a function of the relative compositions and the firing temperature. Films of four different alumina-titania compositions (10, 20, 30 and 40mol% alumina) were prepared and fired at various temperatures in the range from 300 to 1000 °C. The films and powders were amorphous, at any composition, up to about 600 °C. Larger molar contents of Al2O3 were found to have an inhibitory effect on the crystallization of TiO2, while larger contents of TiO2 had only a weak influence on Al2O3 crystallization. The formation of a metastable BETA-Al2TiO5 phase was observed in films at 1000 °
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Thick Film Microsensors Based on Nanosized Semiconducting Oxides Powders
No full textIn materials science, great emphasis is currently being given to work on structures at the nanometer scale in order to study the unique physical properties which derive from size reduction to these dimensions(1). In nanosized materials, the surface-to-bulk ratio is much greater than for coarse materials, so that the surface properties become paramount, which makes them particularly appealing in applications where such properties are exploited, as in gas sensors. Grain size reduction is one of the main factors enhancing the gas sensing properties of semiconducting oxides (Shimizu & Egashira loc cit) and indeed sharp increases in sensitivity are to be expected when the grain size becomes smaller than the space-charge depth according to currently-accepted mechanisms(2). Thus, the application of nanostructured materials, both as powders and thin films, in gas sensors is rapidly arousing the scientific community interest(3-10).
Both chemical and physical methods for the production of nanosized ceramic powders are being widely investigated(11-13). Controlled, ultrafine and homogeneously-sized ceramic powders can be prepared using chemical methods(14), and the first step in keeping full control of the microstructure of a dense or porous ceramic product is to control the preparation method of the starting powders. Chemical processing is particularly important for heterometallic oxides because conventional production methods (solid-state reactions at high temperatures) have several problems involving grain growth, changes in stoichiometry, and ease of second phase formation(15).
The present paper reviews our work on the use of semiconducting oxide powders for the fabrication of thick films by screen-printing technology(16-22). A comparison of the results of using commercial and chemically-processed nanosized powders has demonstrated that the performance of subsequent sensors is improved by employing the latter. This approach has been seldom reported in the relevant literature; in fact, while there are several groups working on thick-film gas sensors(23-27), only a few used nanosized powders for the processing of thick films(28-30). Moreover, the purpose of our study being for gas sensors in environmental monitoring applications, outdoor field tests were performed using the prepared thick-film prototype sensors(31,32). Previously, sensors based on semiconducting oxides have been used only for the control of indoor air quality(33), and for the control of air quality inside cars for passengers comfort(34,35)
X-RAY PHOTOELECTRON-SPECTROSCOPY INVESTIGATION OF CORROSION BEHAVIOR OF ASTM C71640 COPPER-NICKEL ALLOY IN SEAWATER
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